1. Field of the Invention
The present invention relates to the field of portable terminals and more particularly to an apparatus and method for reducing battery power consumption and Central Processing Unit (CPU) utilization rate in a portable terminal.
2. Description of the Related Art
SIM (Subscriber Identity Module) polling makes it possible to identify SIM card installation or non-installation in a portable terminal and makes it possible for a user to use a network service.
SIM card removal or non-removal is identified at an interval of 30 seconds in accordance with the 3rd Generation Partnership Project (3GPP) standard Technical Specification (TS) 31.101 (see www.3GPP.org) In addition, a Universal Integrated Circuit Card (UICC) is another technology that can include several cards such as a Universal SIM (USIM) card, a SIM card, etc. that may be used to provide several kinds of services in a portable terminal.
In order to identify SIM card installation or non-installation, there is a need for polling between a SIM card and a portable terminal. This polling is carried out regardless of the type of an installed card, i.e., basic SIM card, a USIM card, etc. and regardless of a mode (e.g., a Packet Switched (PS) mode, a Circuit Switched (CS) mode, a SIM card access mode) of the portable terminal.
Typically, the portable terminal is mostly in an idle state except when being in voice call telephony or using a packet call (e.g., data transmission). However, even in the idle state, much polling occurs between the portable terminal and the SIM card. This is a cause of a waste of resources of a controller (i.e., a CPU) of the portable terminal.
This unnecessary polling consumes system resources or controller resources, thus increasing battery power consumption and problematically reduces a time of the use of the portable terminal.